Color-based object recognition

摘要

The purpose is to arrive at recognition of multicolored objects invariant to a substantial change in viewpoint, object geometry and illumination. Assuming dichromatic reflectance and white illumination, it is shown that normalized color rgb, saturation S and hue H, and the newly proposed color models c1c2c3andl1l2l3 are all invariant to a change in viewing direction, object geometry and illumination. Further, it is shown that hue H and l1l2l3 are also invariant to highlights. Finally, a change in spectral power distribution of the illumination is considered to propose a new color constant color model m1m2m3. To evaluate the recognition accuracy differentiated for the various color models, experiments have been carried out on a database consisting of 500 images taken from 3-D multicolored man-made objects. The experimental results show that highest object recognition accuracy is achieved by l1l2l3 and hue H followed by c1c2c3, normalized color rgb and m1m2m3 under the constraint of white illumination. Also, it is demonstrated that recognition accuracy degrades substantially for all color features other than m1m2m3 with a change in illumination color. The recognition scheme and images are available within the PicToSeek and Pic2Seek systems on-line at: http: //www.wins.uva.nl/research/isis/zomax/.